Contents
Key Stage 2
Meaning
A picture of a microscope.
A microscope is piece of equipment used to make small objects appear larger.
About Microscopes
- Microscopes can be used to see things too small for our eyes to see.
- Micro means 'small' and scope means 'small'.
Microscope Images
Key Stage 3
Meaning
A microscope is a piece of equipment used to make small objects appear larger.
About Microscopes
- Microscopes use convex lenses to magnify an image.
- The parts of the microscope are shown in the diagram below:
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- Eyepiece Lens - This is the lens that you look down.
- Coarse Focussing Wheel - This moves the stage by a large amount to bring the image into focus (make the image clear and not blurry).
- Fine Focussing Wheel - This moves the stage by a small amount to focus the image carefully (make the image clear and not blurry).
- Objective Lens - This is the lens next to the specimen that magnifies the image.
- Stage - This is where the sample is placed.
- Light Source - This can be a lamp or a mirror used to shine light through the specimen.
Preparing Specimens
To see an object clearly with a microscope a specimen must be prepared first.
- 1. A small specimen is placed on a glass slide.
- 2. A dye is used to colour the specimen so it can be seen more easily under the microscope.
- 3. A cover slip is placed on the specimen to flatten it.
- 4. Tissue is used to absorb any excess dye.
- 5. The glass slide is placed on the microscope stage.
Key Stage 4
Meaning
A light microscope is a device used to observe small objects using visible light.
About Light Microscopes
- A light microscope cannot be used to view anything smaller than about 0.2 micrometres.
- Light microscopes can be used to view objects as small as bacteria but cannot be used to view viruses.
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- Eyepiece Lens - This is the lens that you look down.
- Coarse Focussing Wheel - This moves the stage by a large amount to bring the image into focus (make the image clear and not blurry).
- Fine Focussing Wheel - This moves the stage by a small amount to focus the image carefully (make the image clear and not blurry).
- Objective Lens - This is the lens next to the specimen that magnifies the image.
- Stage - This is where the sample is placed.
- Light Source - This can be a lamp or a mirror used to shine light through the specimen.
Magnification Equation
Image Size = Object Size X Magnification
\(Magnification = \frac{ImageSize}{ObjectSize}\)
Preparing Specimens
To see an object clearly with a microscope a specimen must be prepared first.
- 1. A small specimen is placed on a glass slide.
- 2. A dye is used to colour the specimen so it can be seen more easily under the microscope.
- 3. A cover slip is placed on the specimen to flatten it.
- 4. Tissue is used to absorb any excess dye.
- 5. The glass slide is placed on the microscope stage.
References
AQA
- Light microscopes, page 11, GCSE Biology, Hodder, AQA
- Light microscopes, page 11, GCSE Combined Science Trilogy 1, Hodder, AQA
- Light microscopes, pages 12, 13, GCSE Biology; The Revision Guide, CGP, AQA
- Light microscopes, pages 12, 13, GCSE Combined Science; The Revision Guide, CGP, AQA
- Light microscopes, pages 25, 26, GCSE Biology, CGP, AQA
- Light microscopes, pages 25, 26, GCSE Combined Science Trilogy; Biology, CGP, AQA
- Light microscopes, pages 4-5, GCSE Biology; Third Edition, Oxford University Press, AQA
- Microscopes, pages 12, 13, GCSE Biology; The Revision Guide, CGP, AQA
- Microscopes, pages 12, 13, GCSE Combined Science; The Revision Guide, CGP, AQA
- Microscopes, pages 25-27, 292, GCSE Combined Science Trilogy; Biology, CGP, AQA
- Microscopes, pages 25-27, 372, GCSE Biology, CGP, AQA
- Microscopes; observing onion cells, pages 25-27, GCSE Biology, CGP, AQA
- Microscopes; observing onion cells, pages 25-27, GCSE Combined Science Trilogy; Biology, CGP, AQA